The present invention relates to integrated circuit devices and, more particularly, to integrated circuit devices having passive devices thereon and methods of forming the same.
Integrated circuit devices are being introduced into a variety of different electronic products in place of discrete circuits as they may reduce the cost and the size and/or package complexity of the electronic circuitry included in such devices. Such integrated circuit devices, in some instances, may be referred to as system-on-chip (SOC) devices. Various commercial products in which such integrated circuit devices are being incorporated operate at the radio frequency (RF) band, such as wireless communication devices. In such devices, passive electronic components, such as an inductor or capacitor, are generally essential elements in analog circuitry and/or radio frequency circuits incorporated in the integrated circuit devices. The Quality factor (Q) is a commonly used indicator of performance of an inductor in an integrated circuit device. Q is a measurement of the relationship between power loss and energy storage in an inductor as expressed by the following equation:
                    Q        =                                            ω              *              Maximum              ⁢                                                          ⁢              energy              ⁢                                                          ⁢              stored              ⁢                                                          ⁢              per              ⁢                                                          ⁢              cycle                        ⁢                                                                      Average            ⁢                                                  ⁢            power            ⁢                                                  ⁢            dissipated            ⁢                                                  ⁢            per            ⁢                                                  ⁢            cycle                                              (        1        )            where ω is the angular frequency and Q is the quality factor.
In operation, devices such as inductors generate magnetic fields. Various effects, such as eddy currents, may arise due to the presence of such magnetic fields passing into the integrated circuit device, which may reduce Q for the inductor. Various such effects are illustrated schematically in the perspective views of the FIGS. 1A and 1B. As shown in FIGS. 1A and 1B, an integrated circuit (semiconductor) substrate 10 has an interlayer dielectric layer 40 thereon and an inductor 50 on a top surface of the interlayer dielectric layer 40. The inductor 50 generates a magnetic field 60 that passes into the substrate 10 and the interlayer dielectric layer 40. Furthermore, the magnetic field 60 generates eddy currents 70 in the integrated circuit substrate 10. In addition to the undesirable eddy currents 70, the inductor 50 may also create problems related to substrate noise coupling and a parasitic capacitance may be established between the inductor 50 and a shield pattern 20 formed in the interlayer dielectric layer 40 between the integrated circuit substrate 10 and the inductor 50.